Grate



Sept. 5, 1933. J, 5 THOMPSON 1,925,347

GRATE Filed Aug. 19, 1930 %NY;NT RW ATTORN EYS Patented Sept. 5, 1933 PATENT OFFICE 1,925,347 GRATE James S. Thompson, New Rochelle, N. Y., as

Signor, by mesne assignments, to Waugh Equipment Company, New York, N. Y., a; corporation of Maine Application August 19, 1930. Serial No. 476,266

Claims.

This invention relates to grate bars especially adapted for heavy duty purposes, such as locomotives, boiler furnaces, and the like. More particularly, the invention is concerned with a grate 5 bar which comprises a carrier and a plurality of fuel-supporting units or cross-bars removably mounted thereon, these units preferably having a limited freedom of angular movement relative to the cross-bars.

The object of the invention is to provide a grate bar of the construction described which is substantially lighter in weight and of greater strength than a bar of similar construction in which the parts are made of cast iron. This is accomplished by constructing each unit with a solid part and a hollow part of different materials the two being connected together to form an integral struc ture.

For a better understanding of the invention,

reference may be had to the accompanying drawing, in which Fig. 1 is a cross-sectional View through a grate bar constructed in accordance with this invention,

, illustrating a fuel-supporting unit in side elevation;

Figs. 2 and 3 are sectional views on the lines 22 and 3-3, respectively;

Fig. 4 is a fragmentary view of the grate bar in side elevation; and Fig. 5 is a plan view.

Referring to the drawing, the grate bar comprises a carrier which includes a horizontal web 10 provided with a strengthening rib 11 on its under surface and with a downwardly extending 3 shaker arm 12. Projecting upwardly from the web is a centering flange l3 and at the ends the web is provided with upstanding arms 14 having supporting means, such as projecting trunnions Mounted on the carrier are a plurality of fuelsupporting units, each of which comprises a hollow bottom 16 preferably made of a pair of plates 17 of sheet stock formed with edge flanges 18 along their bottom and lateral edges. These plates are secured together with their flanges in contact by any convenient means such, for example, as by welding the flanges together. The top edges of the plates lie spaced apart and these portions of the plate lie embedded within a solid top generally designated 19.

This top is of cast metal and it is provided on one or both faces with spaced lugs 20-which define vertical passages 21 for the upward flow of air to the fuel. Projecting upwardly from the top of the lugs are fuel-supporting projections 22 preferably arranged in groups of four, two projections of each group lying above a lug and the other two above the main body of the top adjacent the lug. These projections are separated by intersecting air channels 23, 24, the latter communicating with the passages 21 sothat air can flow around all sides of each projection to keep the latter cool and to elfect a wide distribution of air to the fuel. Preferably the lugs at the middle of the top are connected together, as indicated at 25, to provide additional strength at this point. The plates forming the hollow bottom of the unit project upwardly above the lower edges of the lugs, the top edges of the plates, indicated at 26, being overlain by the lower ends of the lugs. The plates are provided with openings 27 so that tongues of the metal 28 may flow through the openings and serve to anchor the plates to the top. Preferably at the midpoint each plate has an upwardly extending bulge 29 to give added strength.

The lower edges of the plates are formed with a recess 30, the shape of which is generally similar to the cross-sectional shape of the carrier and at the entrance to the recess are formed opposed lugs 31. In the rocking of the grate bar, the units have a relative angular movement with respect to the carrier and one or the other of the lugs 31 moves into contact with the under surface of the web, preventing further angular movement of the unit relative to the carrier and locking the unit in position.

Grate bars of the type above generally described are disclosed in the co-pending application of Buckley, Serial No. 338,352, filed February 8, 1929, now Patent No. 1,884,557, October 25, 1932, and all parts of the Buckley bar are commonly made of cast iron. With that construction, the units occasionally crack across in service, the fracture occurring near the midpoint of each unit. When this takes place, the two parts of the unit fall free of the carrier and there is a hole in the grate surface. With the present construction, the hollow bottom is made of sheet steel which will not fracture in use and should the solid cast iron top of the new unit fracture, the two parts will be supported by the hollow bottom and loss of the unit from the carrier will be prevented. Also, it will be observed that with the construction disclosed, a great part of the unit is hollow and this lightens thelconstruction materially without sacrifice of strength.

In my co-pending application, Serial No. 476,263 filed August 19, 1930, there is disclosed a unit similar to the one above described having a solid top and a hollow bottom. In the construction of that application, the plates which form the bottom of each unit are formed with lugs near their upper edges which con form to the lugs 20 on the top, and the solid top has a portion which is received between the plates. In the present construction, the plates are plain except for the edge flange and the upper edges of the plates are embedded in the solid top, the lugs on the top overhanging the upper edges of the plates for a considerable distance. While both constructions are satisfactory and offer substantial advantages over units made of cast iron throughout, the present construction is somewhat cheaper to make than that in the co-pending application identified.

The units constructed in accordance with the present invention may be manufactured at low cost, the plates being formed of sheet steel stock by stamping operations, connected together to form the hollow bottom and then inserted in the mold in which the top is to be cast, the molten metal flowing through the openings near the top edge of the plates so that the hollow bottom and solid top of the unit are firmly secured together.

I claim:

1. A grate oar comprising a longitudinal member having supporting means at its ends, and a plurality of fuel supporting units mounted on said member and projecting beyond the lateral edges of said member, each unit having a top of solid metal and a hollow bottom member of sheet metal, the upper edges of which are embedded in said top from end to end of the latter, said bottom member being closed along its lower edges and having a recess for receiving said longitudinal member, the walls of said recess resting on said longitudinal member.

2. A grate bar comprising a longitudinal member having supporting means at its ends, and a plurality of fuel supporting units mounted on said member and projecting beyond the lateral edges of said member, each unit having a solid top and a hollow bottom member comprising a pair of plates of sheet metal having contacting portions along a part of their edges, said plates having portions embedded in said top and thereby secured to the top and said hollow member having a recess defined by contacting portions of said plates, said longitudinal member entering said recess and engaging the wall thereof to support said unit.

3. In a grate bar, a fuel supporting unit comprising a solid top element, and a bottom element made up of a pair of plates having contacting portions and spaced portions, part of said spaced portions being embedded in said top element, and said bottom element having a recess in its lower edge for reception of a car rier bar, the walls of said recess being defined by contacting portions of. said plates.

4. In a grate bar, a fuel supporting unit comprising a solid top element, and a bottom element made up of a pair of plates having contacting flanges along the bottom and lateral hollow bottom having united portions and spaced portions, certain of the latter being embedded within said solid top and terminating above the lower ends of said lugs, and said bottom being formed with a recess for the reception of a carrier bar, said recess being defined by united portions of said bottom.

JAMES S. THOMPSON. 

